The most widely used interconnect system (which is employed in most electronic devices) employs metal traces that are integrated into a printed circuit board (PCB) or backplane. For this type of system, integrated circuits (ICs) are secured to the PCB so as to be electrically coupled to one or more of the traces, allowing for interchip or chip-to-chip communications. A problem with this arrangement is that the physical limit for data rates or data transmission is being reached, so, as a result, several different types of communications links have been or are being developed: optical and wireless links. Each of these developing technologies employs the use of a transmission medium, namely an optical fiber for optical links and a metal waveguide for wireless links.
Turning to FIGS. 1 and 2, an example of an interconnect system 100 using a wireless link or optical link can be seen. In this example, a transmission medium 104 (which is a metal waveguide or an optical fiber) is integrated into a PCB 102. ICs 106-1 and 102-6 are secured to the PCB 102 and located in proximity to each respective end of the transmission medium 104. Theoretically, then, the transceiver 108-1 and 108-2 (which are optical transceivers for optical links and radio frequency (RF) transceivers for wireless links) can allow for interchip communication between ICs 106-1 and 106-2. In practice, however, this interchip communication is not a simple task. Assuming, for example, that the system 100 employs an optical link, the optical transceivers 108-1 and 108-2 would have an on-die light emitting diode (LED) and/or photodiode (which is difficult with current process technologies), having an optical axis. Usually, the LED (for transmission) is a laser diode, which has a particular wavelength or frequency, and the transmission medium 104 (optical fiber for this example) is dimensioned to accommodate the wavelength of the light emitted from LED. Typically, the transmission medium 104 (optical fiber for this example) is a monomode fiber to improve bandwidth, which has a diameter that is related to the wavelength of the light emitted from LED. For example, for near infrared (i.e., wavelength between about 0.7 μm and about 3 μm), a monomode optical fiber will generally have a diameter between about 8 μm and about 10 μm. Thus, a misalignment (of even a few microns) between the optical axis of the transmission medium 104 (optical fiber for this example) and the optical axis of the LED (or photodiode) may result is a poor interconnect or no interconnect. Therefore, precision machining or other more exotic micro-optical structures would generally be necessary. The same would also be true for metal waveguides; namely, precision machining would generally be necessary for proper alignment. Metallic waveguides for sub-millimeter waves are also quite lossy, substantially limiting the distance over which the waveguides would work.
Therefore, there is a need for an improved interconnect system.
Some other examples of conventional systems are: U.S. Pat. Nos. 5,754,948; 7,768,457; 7,379,713; 7,330,702; 6,967,347; and U.S. Patent Pre-Grant Publ. No. 2009/0009408.